Determination of the modulated structure of the misfit layer compound (LaS)1.196VS2

Single crystal X-ray diffraction was used to determine the modulated structure of the misfit layer compound (LaS)(1.196)VS2. This compound crystallizes in the triclinic system with cell parameters: a(s) = 3.410 (1) Angstrom, b(s) = 5.845(1) Angstrom, c(s) = 11.191(2) Angstrom, alpha approximate to 95.15(4), beta approximate to 84.79(2)degrees, and y approximate to 89.98(2)degrees, q = 0.5978(4)a(s)* - 0.002(1)b(s)* + 0.004(2)c(s)*, and V-s = 221.2(1) Angstrom(3). A (3 + 1)D superspace group, X (1) over bar(alpha,beta,gamma), was used to analyze the complete structure (X is referring to a pseudo C centering). The largest modulation amplitudes are observed for La-S (between La (subsystem 2) and S (subsystem 1)), as well as V-V distances. In connection with the large V-V modulation, we observed the formation of "linear vanadium clusters" that may impact on the transport properties. (C) 2004 Elsevier Ltd. All rights reserved.